Fuel injection pumps

ABSTRACT

A fuel injection pump which includes a rotary drive shaft and which is driven through a device which enables the timing of injection of fuel to an associated engine to be varied in accordance with the speed at which the pump is driven, the device including a cover which has a cylindrical extension projecting into the body portion of the pump and there being provided intermediate the pump and the extension an oil seal.

United States Patent Timms FUEL INJECTION PUMPS [72] Inventor: Colin Thomas Timms, 32 Miletree.

Crescent, Dunstable, Bedfordshire, England [22] Filed: Sept. 29, 1970 [21] Appl. No.: 76,510

[30] Foreign Application Priority Data 7 Sept. 30, 1969 Great Britain ..47,972/69 52 vs. C]. ..123/139 AP [51] Int. Cl ..F02m 39/00 [58] Field of Search ..417/212; l23/l39.l3; 64/25 [56] References Cited UNITED STATES PATENTS 2,722,813 11/1955 Aldinger ..123/l39.l3 2,743,593 5/1956 Bischofi ..64/25 2,829,630 4/1958 Ziesche' ..123/139.l3

151 3,683,879 [4 1 Aug. 15, 1972 3,062,027 1 H1962 Pigeroulet ..64/25 3,091,231 5/1963 Giraudonm, ..123/139.13

FOREIGN PATENTS OR APPLICATIONS 173,903 7/1952 Austria ..123/139 AP 474,535 9/19s2 Italy ..123/139 AP 188,965

Primary Examiner-William L. Freeh Attorney-Holman & Stern ABSTRACT A fuel injection pump which includes a rotary drive shaft and which is driven through a device which enables the timing of injection of fuel to an associated engine to be varied in accordance with the speed at which the pump is driven, the device including a cover which has a cylindrical extension projecting into the body portion of the pump and there being provided intermediate the pump and the extension an oil seal.

6 Claims, 2 Drawing Figures 4/1956 Austria ..123/139 AP PATENTEDAus 15 I972 FIG. 2

INVENTOR an Va Jaw wvu f ATTORNEYS 1 FUEL INJECTION PUMPS BACKGROUND OF THE INVENTION device comprising a hub mounted upon the shaft, a

drive element and speed responsive mean for adjusting the angular relationship between the drive element and the shaft in accordance with the speed at which the pump is driven.

In the past, the aforesaid device has included a cover secured and sealingly engaged with a hub, the cover extending to adjacent a cylindrical surface defined on a member formed on or secured to the input member, with there being provided a seal between said surface and the cover, the seal allowing limited angular movement between the cover and with said surface but providing a liquid seal therebetween to prevent lubricant from within the device escaping. Such devices have not proved satisfactory and it has been found that the lubricant has escaped thereby leading to failure of the device. 7

It is an object of the invention to provide a pump of the kind specified in an improved form.

SUMMARY OF THE INVENTION According to the invention, a pump of the kind specified includes a cover for said device, the cover being secured to and sealingly engaged with said drive element and defining a hollow cylindrical portion which extends about said shaft and within the body portion of the pump, and seal means being provided between the body portion of the pump and the outer peripheral surface of said cylindrical portion of the cover.

One example of a liquid fuel pump in accordance with the invention will now be described with reference to the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional side elevation through part of a pump, and

FIG. 2 is a view taken along the line 2-2 of FIG. 1, the view looking in the direction of the arrows.

DETAILED DESCRIPTION OF THE DRAWINGS A portion of the pump body is shown at 10 and through which extends a driven shaft 11. The pump body accommodates a reciprocable plunger or plungers and these are actuated in known manner by a cam or cams respectively formed on the driven shaft. The shaft is supported by a bearing 12.

Carried on the extending portion of the shaft is a device 13 which includes a hub 14 which is secured to the shaft. The hub is provided with flange portions 15 positioned near the body portion of the pump. Moreover, surrounding the extended hollow cylindrical portion of the hub is a bearing sleeve 16 about which is mounted a hollow cylindrical member 17. The member 17 is provided with an annular flange portion 18 constituting a drive element and the member 17 is retained in position by a circlip.

In use, the flange portion 18 carries a peripherally toothed wheel (not shown) which in use, is driven by a toothed wheel of the engine with which the pump is as sociated.

Defined within the device is a generally annular space 20 and located within the space is a pair of weights 21 with the weights being of part annular form.

In the faces of the weights presented to the flange por- I tions 15 are slots in which are located the flange portions respectively. The weights can therefore move in a radially outwards direction against the action of tension springs 22. Moreover, formed in the opposite faces of the weights are a pair of inclined slots 23 respectively and in which are located slidable members 24 which are carried by and are pivotally mounted upon pins 25 carried by the annular flange portion 18. The arrangement is such that as the weights move outwardly, relative angular movement will take place between the flange portion 18 and the hub 14. The weights move outwardly under the action of centrifugal force and the effect is that the timing of injection of fuel to the engine is adjusted.

The aforesaid mechanism is lubricated by a lubricant which is contained within the aforesaid annular space 20 by means of a cover 26. The cover 26 is of generally cup shaped form having an outwardly extending flange 27 at its open end. The flange 27 is bolted to the flange l8 and a sealing gasket is interposed therebetween to ensure a fluid tight seal. The base wall of the cover is provided with a central aperture through which a portion of the hub extends but the cover is provided with an integral hollow cylindrical portion 28 extending from the periphery of the aperture to within the pump body. Moreover, mounted in the pump body is an oil seal 29 which establishes a liquid seal between the outer cylindrical surface of the portion 28 and the pump body. In this manner, the diameter of the seal 29 is much smaller than the seals in the prior art devices. If desired, a bearing sleeve may be provided between the portion 28 of the cover and the portion of the hub 14 which projects into the pump casing.

Lubricant is supplied to the annular space by means of a groove 30 formed on the shaft 11. In communication with the groove 30 is a drilling 31 which opens into the space. The lubricant enters the space from the interior of the pump body.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

1. A fuel injection pump including a body containing a pump, a driven shaft having a portion extending from the body, and a device for enabling the timing of injection of fuel to an associated engine to be varied in accordance with the speed at which the pump is driven, said device being located externally of the pump body and comprising means secured to the extending portion of the shaft, a drive element, speed responsive means for adjusting the angular relationship between the drive element and the shaft in accordance with the speed at which the pump is driven, a cover for said device secured to and sealingly engaged with said drive element and having a hollow cylindrical portion which surrounds said extending shaft portion and projects into the body of the pump, seal means provided between the body of the pump and the outer peripheral surface of said cylindrical portion of the cover.

2. The pump as claimed in claim 1 in which said means secured to the extending portion of the shaft is a hub and said hollow cylindrical portion which extends and means for imparting relative angular movement to the hub portion and drive element as the weights move outwardly.

5. The fuel injection pump as claimed in claim 4 in which the weights are provided with inclined slots in their faces which are presented to the drive element,

with the drive element mounting a pair of pivotal members engaging within said slots.

6. The fuel injection pump as claimed in claim 5 including spring means for biasing the weights against outward movement. 

1. A fuel injection pump including a body containing a pump, a driven shaft having a portion extending from the body, and a device for enabling the timing of injection of fuel to an associated engine to be varied in accordance with the speed at which the pump is driven, said device being located externally of the pump body and comprising means secured to the extending portion of the shaft, a drive element, speed responsive means for adjusting the angular relationship between the drive element and the shaft in accordance with the speed at which the pump is driven, a cover for said device secured to and sealingly engaged with said drive element and having a hollow cylindrical portion which surrounds said extending shaft portion and projects into the body of the pump, seal means provided between the body of the pump and the outer peripheral surface of said cylindrical portion of the cover.
 2. The pump as claimed in claim 1 in which said means secured to the extending portion of the shaft is a hub and said hollow cylindrical portion which extends into the pump body and which engages said seal means being located about a cylindrical extension of the hub.
 3. The fuel injection pump as claimed in claim 2 including passage means extending from the pump body to a space defined within said cover.
 4. The fuel injection pump as claimed in claim 2 in which the hub defines a pair of outwardly extending flange portions, which guide the outward movement of a pair of weights under the action of centrifugal force and means for imparting relative angular movement to the hub portion and drive element as the weights move outwardly.
 5. The fuel injection pump as cLaimed in claim 4 in which the weights are provided with inclined slots in their faces which are presented to the drive element, with the drive element mounting a pair of pivotal members engaging within said slots.
 6. The fuel injection pump as claimed in claim 5 including spring means for biasing the weights against outward movement. 